In a silver halide color photographic light-sensitive material, a process using a dye-forming coupler which reacts with an oxidized form of an aromatic primary amine-developing agent to form a dye (hereinafter referred to as "coupler") is often applied. In particular, combinations of yellow coupler, cyan coupler, and magenta coupler are generally used for such a color light-sensitive material.
5-pyrazolone couplers are often used as magenta couplers. However, such a 5-pyrazolone coupler is disadvantageous in color reproduction in that it has a side absorption, in the proximity of 430 nm, and that the tail of the longer wavelength side of the absorption curve is not sharp.
As magenta couplers which eliminate these defects, pyrazoloazole couplers have been known as described in Japanese Patent Application (OPI) Nos. 171956/84, 33552/85, and 43659/85 (the term "OPI" as used herein means an "unexamined published application"), and U.S. Pat. Nos. 4,500,630 and 4,540,654.
It is useful to incorporate a sulfite (e.g., sodium sulfite) in the color-developing solution as a preservative. However, if such a pyrazoloazole coupler is used therewith, the dependency of change of color density or gradation on the change of the concentration of sulfite in the developing solution (hereinafter referred to as "dependency of magenta density on sulfite concentration") becomes greater as compared to the conventional 5-pyrazolone coupler. As a result, if the concentration of sulfite in the developing solution changes, the color balance, color reproducibility, or the like changes, deteriorating the image quality. On the other hand, it has been confirmed in processing laboratories that the sulfite concentration varies over a wide range from a fraction to several times the so-called prescribed value. This is believed to be attributable to consumption of sulfite due to oxidation by air or development or excess supplement of sulfite.